Which RL instead of a mineral 10W40?

[Kukulcan]

Hi guys,
please I need your advices...

I used to put Synthetic high quality car oil in my scooter Honda 150cc 12KW at 8.500 rpm
I'm pretty sure that for my scooter, 100% synthetic car oils are better than motorcycle ones since there is no need of an oil suitable also for the gearshift(it hasn't got). That's why I chose this forum section...

This is the point: The manual and the official Honda Service say 10W40, assuming you to use a standard mineral oil like Castrol Act-evo (14 vis at 100°C, no info about HT/HS)

I use it all over the year. In winter time, 10-15 minutes frequent short trips even at 32°F and so, several cold starts. In summer, typical short trips plus some longer ones (70 miles) at high rpm at even 95°F

I'd go for Redline 5w30 since its HT/HS(3.8) is equivalent to the minimum of the 15w40 class and it gives me better flow. Is it a problem the vis at 100°C? Because the Castrol is 14 while the RL is 10.6? This is my only doubt...

Any suggestions? Thanks!

 

[KW]

I think you should stay with a 10W40 oil with no friction modifiers like the Castrol. If you do switch to Redline stay with a 10W40.

A quick email to Redline might be the best way to get a good answer on which one of their oils to use in your scooter.

 

[chevrofreak]

Modern friction modifiers have little if any effect on wet clutches, so using it in an engine with no clutch, and no gears should be fine.

I would probably use Red Line 5w30.

 

[CATERHAM]

Yes RL 5w30 would be fine.
I'd also consider M1 0W-40 which is has the same HTHS vis' but a much higher VI of 185 which means it will be lighter on start-up even in the summer and during warm-up.

 

[Kukulcan]

First of all, thanks for your answers!

I'll ask the final word directly to Redline, anyway, I'm glad you confirm me that the 5W30 could be the better choice among RL.

@CATERHAM

Thanks for the suggestion, I considered also that Mobil1 0W40, that is anyway, among the best oil available, and pretty simpler to find here in Italy, while for the RLs I should always pay the shipping...

But there something you told me I didn't understand.... You suggested Mobil1 0W40 because it has a higher vis index than RL 5W30 and because of this, it gives me better lubrication at start up, both in winter and in summer.
Yes ok, but the RL has lower vis than Mobil1 both at 100° (10.6 vs 13.5) and at 40°(62 vs 75) even though the vis index of M1 is higher. Ok, these are not start up temperatures, but could indicate a little lower vis at my most common startup temp, say beetwen 40-70°F... In the end, RL CCS is 60 Poise at -30°C, while M1 MRV at -40°C is 31,000 cP, which is more liquid at this very low temparatures? Is it possible to guess which could be less vis at, let's say, 32°F?
Thank you again...

 

[KenO]

My old roommate Wayne builds skooters, and is one of the top scooter technicians/customizers in the SE. He's built 150 swap kits for Rukus', built Italjets, TGP's, etc. I think he runs BMW Motorsport Castrol TWS 10W-60 in all of them universally.